Source:

Response:

Stalin rejected neo-Darwinian evolution in favor of Lamarckism.

Mendeleyev's "periodic system of elements" clearly shows how very
important in the history of nature is the emergence of
qualitative
changes out of quantitative changes. The same thing is
shown in
biology by the theory of neo-Lamarckism, to which neo-Darwinism is
yielding place. (Stalin 1906, 304)

More specifically, Stalin rejected the ideas of August Weismann, a
19th-century German biologist, in favor of Trofim Lysenko, a
pseudoscientist who based his ideas on Lamarckism. Weismann, who
accepted Darwin's theory of evolution, disproved Lamarckism and
proposed that germ cells pass on hereditary information; his work was
an early variant of the modern evolutionary synthesis which unites
evolutionary theory with genetics. Stalin appointed Lysenko head of
the Academy of Agricultural Sciences of the Soviet Union, where he had
great political power. (Rossiannov 1993)

Stalin and Lysenko rejected evolution and genetics for ideological, not
biological, reasons. (Stalin was quite ignorant of science in
general.) The class struggle of Marxism contradicts the individual
competition implied by natural selection. More importantly, genetics,
implying that traits were fixed at birth, contradicted the ideal of
moulding and improving traits. Stalin proclaimed genetics a capitalist
pseudo-science.

Stalin was, first and foremost, a Marxist dictator, far above any
allegiance he might have had to any theories concerning the origin of
species, whether Lamarckian or Darwinian. Stalin distrusted scientists
as being prone to free-thinking. Though his persecution of biologists
and biology were particularly egregious (causing appalling damage to
Soviet agriculture), he imprisoned and killed thousands of scientists
and engineers from all fields.

Oppression and murder have been used as tools of statecraft long before
Darwin published his work.

There is no evidence that Darwin's work was used as a justification for
oppression and murder. Stalin doubtless accepted Newton's theory of
gravity, but creationists do not claim that Newton's theory should be
suppressed because Stalin believed it.